Let μ be a nonnegative Radon measure on Rd, which only satisfies the polynomial growth condition. Under this assumption, the authors obtain some weighted weaktype estimates for the commutators generated by the multil...Let μ be a nonnegative Radon measure on Rd, which only satisfies the polynomial growth condition. Under this assumption, the authors obtain some weighted weaktype estimates for the commutators generated by the multilinear CalderSn-Zygmund op- erators and RBMO(μ) functions.展开更多
Let μ be a non-negative Radon measure on Rd which only satisfies the following growth condition that there exists a positive constant C such that μ(B(x,r)) ≤ Crn?for all x∈ Rd, r > 0 and some fixed n ∈ (0,d]. ...Let μ be a non-negative Radon measure on Rd which only satisfies the following growth condition that there exists a positive constant C such that μ(B(x,r)) ≤ Crn?for all x∈ Rd, r > 0 and some fixed n ∈ (0,d]. This paper is interested in the properties of the iterated commutators of multilinear singular integral operators on Morrey spaces?.Precisely speaking, we show that the iterated commutators generated by multilinear singular integrals operators are bounded from to where (Regular Bounded Mean Oscillation space) and 1 qj ≤ pj ∞ with 1/p = 1/p1 + ... + 1/pm and 1/q = 1/q1+ ... + 1/qm.展开更多
Introduction: COVID-19 is a pandemic disease caused by the coronavirus SARS-COV2 appeared in China in 2019. The aim of the study was to evaluate the practice of barrier measures against COVID-19 and to identify associ...Introduction: COVID-19 is a pandemic disease caused by the coronavirus SARS-COV2 appeared in China in 2019. The aim of the study was to evaluate the practice of barrier measures against COVID-19 and to identify associated factors among diabetics followed at Departmental University Hospital Center Ouémé-Plateau, Benin, in 2021. Methods: This was a cross-sectional study conducted from June to August 2021, including diabetics aged 18 and over, hospitalized or received for medical visits in the department of medicine at the target hospital. Data were collected during an interview with each participant thanks to a questionnaire. “Good practice” was defined as regular practice of at least two of three barrier measures: hand washing, physical distancing and mask-wearing. Results: A total of 110 diabetics were included with a female predominance (55.5%) and a mean age of 57 ± 11.3 years. Among them, 89.1% washed their hands, 41.8% respected physical distancing and 12.7% wore a mask. The proportion of good practice was 47.3%. Only 5 practiced the three barrier measures. Only age group was associated with good practice. Conclusion: The study showed a low proportion of good practice of barrier measures against COVID-19 among diabetic people surveyed. It is important to continue the action for COVID-19 prevention among diabetic people in the targeted hospital and in other hospitals in Benin.展开更多
The authors give a natural definition of Morrey spaces for Radon measures which may be non-doubling but satisfy certain growth condition, and investigate the boundedness in these spaces of some classical operators in ...The authors give a natural definition of Morrey spaces for Radon measures which may be non-doubling but satisfy certain growth condition, and investigate the boundedness in these spaces of some classical operators in harmonic analysis and their vector-valued extension.展开更多
Objective:To study the effect of repetitive peripheral magnetic stimulation(rPMS)combined with conventional rehabilitation measures on shoulder dysfunction in early stroke.Methods:60 patients with shoulder dysfunction...Objective:To study the effect of repetitive peripheral magnetic stimulation(rPMS)combined with conventional rehabilitation measures on shoulder dysfunction in early stroke.Methods:60 patients with shoulder dysfunction in early stroke were selected,and all of them were admitted to our hospital from August 2021 to August 2023.The patients were randomly grouped into a control group(conventional rehabilitation measures intervention,30 cases)and an intervention group(rPMS and conventional rehabilitation measures intervention,30 cases)according to the lottery method.The pain scores,shoulder mobility,and motor function scores of the two groups were compared.Results:The pain score was lower in the intervention group,and the shoulder mobility and motor function scores were higher in the intervention group(P<0.05)as compared to that of the control group.Conclusion:The effect of combining rPMS and conventional rehabilitation measures in treating shoulder dysfunction in early stroke was remarkable and should be popularized.展开更多
Let μ be a non-negative Radon measure on R^d which satisfies only some growth conditions. Under this assumption, the boundedness in some Hardy-type spaces is established for a class of maximal Calderón-Zygmund o...Let μ be a non-negative Radon measure on R^d which satisfies only some growth conditions. Under this assumption, the boundedness in some Hardy-type spaces is established for a class of maximal Calderón-Zygmund operators and maximal commutators which are variants of the usual maximal commutators generated by Calder6ón- Zygmund operators and RBMO(μ) functions, where the Hardytype spaces are some appropriate subspaces, associated with the considered RBMO(μ) functions, of the Hardv soace H^I(μ) of Tolsa.展开更多
The boundedness in Lebesgue spaces for commutators generated by multilinear singular integrals and RBMO(μ) functions of Tolsa with non-doubling measures is obtained, provided that‖μ‖=∞and multilinear singular int...The boundedness in Lebesgue spaces for commutators generated by multilinear singular integrals and RBMO(μ) functions of Tolsa with non-doubling measures is obtained, provided that‖μ‖=∞and multilinear singular integrals are bounded from L1(μ)×L1(μ)to L1/2,∞(μ).展开更多
Letμ be a nonnegative Radon measure on Rd which only satisfies μ(B(x,r)) ≤ Corn for all x ∈ Rd,r > 0,and some fixed constants Co > 0 and n ∈ (0,d].In this paper,some weighted weak type estimates with Aρp,(log...Letμ be a nonnegative Radon measure on Rd which only satisfies μ(B(x,r)) ≤ Corn for all x ∈ Rd,r > 0,and some fixed constants Co > 0 and n ∈ (0,d].In this paper,some weighted weak type estimates with Aρp,(log L)σ (μ) weights are established for the commutators generated by Calderón-Zygmund singular integral operators with RBMO(μ) functions.展开更多
Let μ be a Radon measure on Rd which may be non-doubling. The only condition that μ must satisfy is μ(B(x,r)) ≤ Urn for all x∈Rd, r 〉 0 and for some fixed 0 〈 n 〈 d. In this paper, under this assumption, w...Let μ be a Radon measure on Rd which may be non-doubling. The only condition that μ must satisfy is μ(B(x,r)) ≤ Urn for all x∈Rd, r 〉 0 and for some fixed 0 〈 n 〈 d. In this paper, under this assumption, we prove that 0-type Calder6n-Zygmund operator which is bounded on L2 (μ) is also bounded from L^∞(μ) into RBMO (μ) and from Hb (μ) into L1(μ). According to the interpolation theorem introduced by Tolsa, the LP(μ)-boundedness (1 〈 p 〈 ∞) is established for θ-type Calder6n-Zygmund operators. Via a sharp maximal operator, it is shown that commutators and multilinear commutators of θ-type CMderθn-Zygmundoperator with RBMO (μ) function are bounded on LP(μ) (1 〈 p 〈 ∞).展开更多
Let (y, d, dλ) be (Rn, |·|,μ), where |·| is the Euclidean distance, μ is a nonnegative Radon measure on Rn satisfying the polynomial growth condition, or the Gauss measure metric space (Rn, |...Let (y, d, dλ) be (Rn, |·|,μ), where |·| is the Euclidean distance, μ is a nonnegative Radon measure on Rn satisfying the polynomial growth condition, or the Gauss measure metric space (Rn, |·|,dγ), or the space (S, d, p), where S - Rn×R+ is the (ax + b)-group, d is the left-invariant Riemannian metric and p is the right Haar measure on S with exponential growth. In this paper, the authors introduce and establish some properties of the atomic Hardy-type spaces {Xs(Y))0〈s≤∞ and the BM0-type spaces {BM0(y, s)}0〈s≤∞. Let Hi(Y) be the known atomic Hardy space and L01(y) the subspace of f ∈ L1(Y) with integral 0. The authors prove that the dual space of Xs(Y) is SM0(Y,s) when s∈ (0, ∞), Xs(Y) = H1(Y) when s ∈ (0, 1], and X∞(y) = L01(Y) (or L1(Y)). As applications, the authors show that if T is a linear operator bounded from H1 (Y) to L1 (Y) and from L1(y) to L1,∞(Y), then for all r ∈ (1, ∞) and s ∈ (r, ∞], T is bounded from Xr(y) to the Lorentz space L1,8(y), which applies to the Calderon-Zygmund operator on (Rn, |·|,μ), the imaginary powers of the 0rnstein-Uhlenbeck operator on (Rn, |·|,dγ) and the spectral operator associated with the spectral multiplier on (S, d, p). All these results generalize the corresponding results of Sweezy, Abu-Shammala and Torchinsky on Euclidean spaces.展开更多
Under the assumption that μ is a non-doubling measure on R^d which only satisfies the polynomial growth condition, the authors obtain the boundedness of the multilinear fractional integrals on Morrey spaces, weak-Mor...Under the assumption that μ is a non-doubling measure on R^d which only satisfies the polynomial growth condition, the authors obtain the boundedness of the multilinear fractional integrals on Morrey spaces, weak-Morrey spaces and Lipschitz spaces associated with it, which, in the case when μ is the d-dimensional Lebesgue measure, also improve the known results.展开更多
Let μ be a nonnegative Radon measure on Rd which satisfies the polynomial growth condition that there exist positive constants Co and n ∈ (0,d) such that, for all x ∈ Rd and r 〉 0, μ(B(x, r))≤ Corn, where ...Let μ be a nonnegative Radon measure on Rd which satisfies the polynomial growth condition that there exist positive constants Co and n ∈ (0,d) such that, for all x ∈ Rd and r 〉 0, μ(B(x, r))≤ Corn, where B(x, r) denotes the open ball centered at x and having radius r. In this paper, we show that, if μ(Rd) 〈∞, then the boundedness of a Calderdn-Zygmund operator T on L2(μ) is equivalent to that of T from the localized atomic Hardy space h1(μ) to L1,∞(μ) or from h1(μ) to L1(μ).展开更多
Let μ be a Borel measure on R^d which may be non doubling. The only condition that μ must satisfy is μ(Q) ≤ col(Q)^n for any cube Q belong to R^d with sides parallel to the coordinate axes and for some fixed ...Let μ be a Borel measure on R^d which may be non doubling. The only condition that μ must satisfy is μ(Q) ≤ col(Q)^n for any cube Q belong to R^d with sides parallel to the coordinate axes and for some fixed n with 0 〈 n ≤ d. The purpose of this paper is to obtain a boundedness property of fractional integrals in Hardy spaces H^1(μ).展开更多
The performance of clay-pile-pier system under earthquake shaking was comprehensively examined via three-dimensional finite element analyses,in which the complex stress-strain relationships of a clay and piled pier sy...The performance of clay-pile-pier system under earthquake shaking was comprehensively examined via three-dimensional finite element analyses,in which the complex stress-strain relationships of a clay and piled pier system were depicted by a hyperbolic-hysteretic and an equivalent elastoplastic model,respectively.One hundred twenty ground motions with varying peak accelerations were considered,along with the variations in bridge superstructure mass and pile flexural rigidity.Comprehensive comparison studies suggested that peak pile-cap acceleration and peak pile-cap velocity are the optimal ground motion intensity measures for seismic responses of the pier and the pile,respectively.Furthermore,based on two optimal ground motion intensity measures and using curvature ductility to quantify different damage states,seismic fragility analyses were performed.The pier generally had no evident damage except when the bridge girder mass was equal to 960 t,which seemed to be comparatively insensitive to the varying pile flexural rigidity.In comparison,the pile was found to be more vulnerable to seismic damage and its failure probabilities tended to clearly reduce with the increment of pile flexural rigidity,while the influence of the bridge girder mass was relatively minor.展开更多
There are several shape measures for quantitative variables, some of which can also be applied to ordinal variables. In quantitative variables, symmetry, peakedness, and kurtosis are essential properties to evaluate t...There are several shape measures for quantitative variables, some of which can also be applied to ordinal variables. In quantitative variables, symmetry, peakedness, and kurtosis are essential properties to evaluate the deviation from assumptions, particularly normality. They aid in selecting the most appropriate method for estimating parameters and testing hypotheses. Initially, these properties serve a descriptive role in qualitative variables. Once defined, they can be considered to check for non-compliance with assumptions and to propose modifications for testing procedures. The objective of this article is to present three measures of the shape of the distribution of a qualitative variable. The concepts of qualitative asymmetry and peakedness are defined. The measurement of the first concept involves calculating the average frequency difference between qualitative categories matched by frequency homogeneity or proximity. For the second concept, the peak-to-shoulder difference and the qualitative percentile kurtosis are taken into consideration. This last measurement is a less effective option than the peak-to-shoulder difference to measure peakedness. A simulated example of the application of these three measures is given and the paper closes with some conclusions and suggestions.展开更多
There are several shape measures for quantitative variables, some of which can also be applied to ordinal variables. In quantitative variables, symmetry, peakedness, and kurtosis are essential properties to evaluate t...There are several shape measures for quantitative variables, some of which can also be applied to ordinal variables. In quantitative variables, symmetry, peakedness, and kurtosis are essential properties to evaluate the deviation from assumptions, particularly normality. They aid in selecting the most appropriate method for estimating parameters and testing hypotheses. Initially, these properties serve a descriptive role in qualitative variables. Once defined, they can be considered to check for non-compliance with assumptions and to propose modifications for testing procedures. The objective of this article is to present three measures of the shape of the distribution of a qualitative variable. The concepts of qualitative asymmetry and peakedness are defined. The measurement of the first concept involves calculating the average frequency difference between qualitative categories matched by frequency homogeneity or proximity. For the second concept, the peak-to-shoulder difference and the qualitative percentile kurtosis are taken into consideration. This last measurement is a less effective option than the peak-to-shoulder difference to measure peakedness. A simulated example of the application of these three measures is given and the paper closes with some conclusions and suggestions.展开更多
The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(R...The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(RCZ) is built. The formula for an ultimate cutting force is established based on the limit equilibrium principle. The relationship between digital drilling parameters(DDP) and the c-φ parameter(DDP-cφ formula, where c refers to the cohesion and φ refers to the internal friction angle) is derived, and the response of drilling parameters and cutting ratio to the strength parameters is analyzed. The drillingbased measuring method for the c-φ parameter of rock is constructed. The laboratory verification test is then completed, and the difference in results between the drilling test and the compression test is less than 6%. On this basis, in-situ rock drilling tests in a traffic tunnel and a coal mine roadway are carried out, and the strength parameters of the surrounding rock are effectively tested. The average difference ratio of the results is less than 11%, which verifies the effectiveness of the proposed method for obtaining the strength parameters based on digital drilling. This study provides methodological support for field testing of rock strength parameters.展开更多
Introduction: The management of hypertension is mostly based on pharmacotherapy and hygienic and dietary measures (HDMs) for which little data is available in Cameroon. The concern to improve the quality of life of hy...Introduction: The management of hypertension is mostly based on pharmacotherapy and hygienic and dietary measures (HDMs) for which little data is available in Cameroon. The concern to improve the quality of life of hypertensive patients led us to study the knowledge, compliance and effect of HDMs among Cameroonian hypertensive patients. Methods: This was a cross-sectional study carried out at the Douala General Hospital;the census of patients was carried out from 05 March to 10 May 2018. The data evaluated were knowledge and compliance with HDMs with an inference of their effect on blood pressure control. Results: We recruited 330 participants at mean age of 60 ± 11 years, 37.9% men;57.3% with blood pressure (BP) controlled. Out of 330 subjects, 308 (93.3%) who had been educated about dietary health measures for hypertension were assessed on knowledge, compliance and effect of these measures against 22 (6.7%) who had never heard about them. Around 85.7% of participants had good knowledge of HDMs and 78.9% had good compliance with them. There was no statistically significant influence of knowledge and compliance with HDMs on blood pressure control. Conclusion: The level of knowledge and adherence to HDMs of hypertensive patients at the Douala General Hospital was appreciable. It is however appropriate for physicians to intensify patient education on HDMs and BP control.展开更多
基金supported by National Natural Science Foundation of China (10701078)supported by National Science Foundation for Distinguished Young Scholars (10425106)
文摘Let μ be a nonnegative Radon measure on Rd, which only satisfies the polynomial growth condition. Under this assumption, the authors obtain some weighted weaktype estimates for the commutators generated by the multilinear CalderSn-Zygmund op- erators and RBMO(μ) functions.
文摘Let μ be a non-negative Radon measure on Rd which only satisfies the following growth condition that there exists a positive constant C such that μ(B(x,r)) ≤ Crn?for all x∈ Rd, r > 0 and some fixed n ∈ (0,d]. This paper is interested in the properties of the iterated commutators of multilinear singular integral operators on Morrey spaces?.Precisely speaking, we show that the iterated commutators generated by multilinear singular integrals operators are bounded from to where (Regular Bounded Mean Oscillation space) and 1 qj ≤ pj ∞ with 1/p = 1/p1 + ... + 1/pm and 1/q = 1/q1+ ... + 1/qm.
文摘Introduction: COVID-19 is a pandemic disease caused by the coronavirus SARS-COV2 appeared in China in 2019. The aim of the study was to evaluate the practice of barrier measures against COVID-19 and to identify associated factors among diabetics followed at Departmental University Hospital Center Ouémé-Plateau, Benin, in 2021. Methods: This was a cross-sectional study conducted from June to August 2021, including diabetics aged 18 and over, hospitalized or received for medical visits in the department of medicine at the target hospital. Data were collected during an interview with each participant thanks to a questionnaire. “Good practice” was defined as regular practice of at least two of three barrier measures: hand washing, physical distancing and mask-wearing. Results: A total of 110 diabetics were included with a female predominance (55.5%) and a mean age of 57 ± 11.3 years. Among them, 89.1% washed their hands, 41.8% respected physical distancing and 12.7% wore a mask. The proportion of good practice was 47.3%. Only 5 practiced the three barrier measures. Only age group was associated with good practice. Conclusion: The study showed a low proportion of good practice of barrier measures against COVID-19 among diabetic people surveyed. It is important to continue the action for COVID-19 prevention among diabetic people in the targeted hospital and in other hospitals in Benin.
基金the 21st century COE program at Graduate School of Mathemtical Sciences The University of Tokyo and the sceond author is supported by Fjyukai foundation
文摘The authors give a natural definition of Morrey spaces for Radon measures which may be non-doubling but satisfy certain growth condition, and investigate the boundedness in these spaces of some classical operators in harmonic analysis and their vector-valued extension.
文摘Objective:To study the effect of repetitive peripheral magnetic stimulation(rPMS)combined with conventional rehabilitation measures on shoulder dysfunction in early stroke.Methods:60 patients with shoulder dysfunction in early stroke were selected,and all of them were admitted to our hospital from August 2021 to August 2023.The patients were randomly grouped into a control group(conventional rehabilitation measures intervention,30 cases)and an intervention group(rPMS and conventional rehabilitation measures intervention,30 cases)according to the lottery method.The pain scores,shoulder mobility,and motor function scores of the two groups were compared.Results:The pain score was lower in the intervention group,and the shoulder mobility and motor function scores were higher in the intervention group(P<0.05)as compared to that of the control group.Conclusion:The effect of combining rPMS and conventional rehabilitation measures in treating shoulder dysfunction in early stroke was remarkable and should be popularized.
基金Program for New Century Excellent Talents in University(NCET-04-0142)of China
文摘Let μ be a non-negative Radon measure on R^d which satisfies only some growth conditions. Under this assumption, the boundedness in some Hardy-type spaces is established for a class of maximal Calderón-Zygmund operators and maximal commutators which are variants of the usual maximal commutators generated by Calder6ón- Zygmund operators and RBMO(μ) functions, where the Hardytype spaces are some appropriate subspaces, associated with the considered RBMO(μ) functions, of the Hardv soace H^I(μ) of Tolsa.
基金This work was partially supported by Scientific Research Fund of Hunan Provincial Education Department(Grant No.06B059)the Natural Science Foundation of Hunan Province of China(Grant No.06JJ5012)the National Natural Science Foundation of China(Grant Nos.60474070 and 10671062)
文摘The boundedness in Lebesgue spaces for commutators generated by multilinear singular integrals and RBMO(μ) functions of Tolsa with non-doubling measures is obtained, provided that‖μ‖=∞and multilinear singular integrals are bounded from L1(μ)×L1(μ)to L1/2,∞(μ).
基金This work was partly supported by the National Natural Science Foundation of China (Grant No.10671210)the National Science Foundation for Distinguished Young Scholars (Grant No.10425106)the Program for New Century Excellent Talents in University of the Ministry of Education of China (Grant No.04-0142)
文摘Letμ be a nonnegative Radon measure on Rd which only satisfies μ(B(x,r)) ≤ Corn for all x ∈ Rd,r > 0,and some fixed constants Co > 0 and n ∈ (0,d].In this paper,some weighted weak type estimates with Aρp,(log L)σ (μ) weights are established for the commutators generated by Calderón-Zygmund singular integral operators with RBMO(μ) functions.
基金Supported by National Natural Science Foundation of China (No.10371087)Natural Science Foundation of Education Committee of Anhui Province (No.KJ2011A138, No.KJ2012B116)
文摘Let μ be a Radon measure on Rd which may be non-doubling. The only condition that μ must satisfy is μ(B(x,r)) ≤ Urn for all x∈Rd, r 〉 0 and for some fixed 0 〈 n 〈 d. In this paper, under this assumption, we prove that 0-type Calder6n-Zygmund operator which is bounded on L2 (μ) is also bounded from L^∞(μ) into RBMO (μ) and from Hb (μ) into L1(μ). According to the interpolation theorem introduced by Tolsa, the LP(μ)-boundedness (1 〈 p 〈 ∞) is established for θ-type Calder6n-Zygmund operators. Via a sharp maximal operator, it is shown that commutators and multilinear commutators of θ-type CMderθn-Zygmundoperator with RBMO (μ) function are bounded on LP(μ) (1 〈 p 〈 ∞).
基金Supported by National Natural Science Foundation of China (Grant No. 10871025)
文摘Let (y, d, dλ) be (Rn, |·|,μ), where |·| is the Euclidean distance, μ is a nonnegative Radon measure on Rn satisfying the polynomial growth condition, or the Gauss measure metric space (Rn, |·|,dγ), or the space (S, d, p), where S - Rn×R+ is the (ax + b)-group, d is the left-invariant Riemannian metric and p is the right Haar measure on S with exponential growth. In this paper, the authors introduce and establish some properties of the atomic Hardy-type spaces {Xs(Y))0〈s≤∞ and the BM0-type spaces {BM0(y, s)}0〈s≤∞. Let Hi(Y) be the known atomic Hardy space and L01(y) the subspace of f ∈ L1(Y) with integral 0. The authors prove that the dual space of Xs(Y) is SM0(Y,s) when s∈ (0, ∞), Xs(Y) = H1(Y) when s ∈ (0, 1], and X∞(y) = L01(Y) (or L1(Y)). As applications, the authors show that if T is a linear operator bounded from H1 (Y) to L1 (Y) and from L1(y) to L1,∞(Y), then for all r ∈ (1, ∞) and s ∈ (r, ∞], T is bounded from Xr(y) to the Lorentz space L1,8(y), which applies to the Calderon-Zygmund operator on (Rn, |·|,μ), the imaginary powers of the 0rnstein-Uhlenbeck operator on (Rn, |·|,dγ) and the spectral operator associated with the spectral multiplier on (S, d, p). All these results generalize the corresponding results of Sweezy, Abu-Shammala and Torchinsky on Euclidean spaces.
基金Supported by the National Natural Science Foundation of China(No.10871025)
文摘Under the assumption that μ is a non-doubling measure on R^d which only satisfies the polynomial growth condition, the authors obtain the boundedness of the multilinear fractional integrals on Morrey spaces, weak-Morrey spaces and Lipschitz spaces associated with it, which, in the case when μ is the d-dimensional Lebesgue measure, also improve the known results.
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 11171027, 11101339) and the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20120003110003).
文摘Let μ be a nonnegative Radon measure on Rd which satisfies the polynomial growth condition that there exist positive constants Co and n ∈ (0,d) such that, for all x ∈ Rd and r 〉 0, μ(B(x, r))≤ Corn, where B(x, r) denotes the open ball centered at x and having radius r. In this paper, we show that, if μ(Rd) 〈∞, then the boundedness of a Calderdn-Zygmund operator T on L2(μ) is equivalent to that of T from the localized atomic Hardy space h1(μ) to L1,∞(μ) or from h1(μ) to L1(μ).
文摘Let μ be a Borel measure on R^d which may be non doubling. The only condition that μ must satisfy is μ(Q) ≤ col(Q)^n for any cube Q belong to R^d with sides parallel to the coordinate axes and for some fixed n with 0 〈 n ≤ d. The purpose of this paper is to obtain a boundedness property of fractional integrals in Hardy spaces H^1(μ).
基金National Natural Science Foundation of China under Grant Nos.52178353,51808421the Fundamental Research Funds for the Central Universities(WUT:2020III043)。
文摘The performance of clay-pile-pier system under earthquake shaking was comprehensively examined via three-dimensional finite element analyses,in which the complex stress-strain relationships of a clay and piled pier system were depicted by a hyperbolic-hysteretic and an equivalent elastoplastic model,respectively.One hundred twenty ground motions with varying peak accelerations were considered,along with the variations in bridge superstructure mass and pile flexural rigidity.Comprehensive comparison studies suggested that peak pile-cap acceleration and peak pile-cap velocity are the optimal ground motion intensity measures for seismic responses of the pier and the pile,respectively.Furthermore,based on two optimal ground motion intensity measures and using curvature ductility to quantify different damage states,seismic fragility analyses were performed.The pier generally had no evident damage except when the bridge girder mass was equal to 960 t,which seemed to be comparatively insensitive to the varying pile flexural rigidity.In comparison,the pile was found to be more vulnerable to seismic damage and its failure probabilities tended to clearly reduce with the increment of pile flexural rigidity,while the influence of the bridge girder mass was relatively minor.
文摘There are several shape measures for quantitative variables, some of which can also be applied to ordinal variables. In quantitative variables, symmetry, peakedness, and kurtosis are essential properties to evaluate the deviation from assumptions, particularly normality. They aid in selecting the most appropriate method for estimating parameters and testing hypotheses. Initially, these properties serve a descriptive role in qualitative variables. Once defined, they can be considered to check for non-compliance with assumptions and to propose modifications for testing procedures. The objective of this article is to present three measures of the shape of the distribution of a qualitative variable. The concepts of qualitative asymmetry and peakedness are defined. The measurement of the first concept involves calculating the average frequency difference between qualitative categories matched by frequency homogeneity or proximity. For the second concept, the peak-to-shoulder difference and the qualitative percentile kurtosis are taken into consideration. This last measurement is a less effective option than the peak-to-shoulder difference to measure peakedness. A simulated example of the application of these three measures is given and the paper closes with some conclusions and suggestions.
文摘There are several shape measures for quantitative variables, some of which can also be applied to ordinal variables. In quantitative variables, symmetry, peakedness, and kurtosis are essential properties to evaluate the deviation from assumptions, particularly normality. They aid in selecting the most appropriate method for estimating parameters and testing hypotheses. Initially, these properties serve a descriptive role in qualitative variables. Once defined, they can be considered to check for non-compliance with assumptions and to propose modifications for testing procedures. The objective of this article is to present three measures of the shape of the distribution of a qualitative variable. The concepts of qualitative asymmetry and peakedness are defined. The measurement of the first concept involves calculating the average frequency difference between qualitative categories matched by frequency homogeneity or proximity. For the second concept, the peak-to-shoulder difference and the qualitative percentile kurtosis are taken into consideration. This last measurement is a less effective option than the peak-to-shoulder difference to measure peakedness. A simulated example of the application of these three measures is given and the paper closes with some conclusions and suggestions.
基金supported by the National Key Research and Development Program of China(No.2023YFC2907600)the National Natural Science Foundation of China(Nos.42077267,42277174 and 52074164)+2 种基金the Natural Science Foundation of Shandong Province,China(No.ZR2020JQ23)the Opening Project of State Key Laboratory of Explosion Science and Technology,Beijing Institute of Technology(No.KFJJ21-02Z)the Fundamental Research Funds for the Central Universities,China(No.2022JCCXSB03).
文摘The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(RCZ) is built. The formula for an ultimate cutting force is established based on the limit equilibrium principle. The relationship between digital drilling parameters(DDP) and the c-φ parameter(DDP-cφ formula, where c refers to the cohesion and φ refers to the internal friction angle) is derived, and the response of drilling parameters and cutting ratio to the strength parameters is analyzed. The drillingbased measuring method for the c-φ parameter of rock is constructed. The laboratory verification test is then completed, and the difference in results between the drilling test and the compression test is less than 6%. On this basis, in-situ rock drilling tests in a traffic tunnel and a coal mine roadway are carried out, and the strength parameters of the surrounding rock are effectively tested. The average difference ratio of the results is less than 11%, which verifies the effectiveness of the proposed method for obtaining the strength parameters based on digital drilling. This study provides methodological support for field testing of rock strength parameters.
文摘Introduction: The management of hypertension is mostly based on pharmacotherapy and hygienic and dietary measures (HDMs) for which little data is available in Cameroon. The concern to improve the quality of life of hypertensive patients led us to study the knowledge, compliance and effect of HDMs among Cameroonian hypertensive patients. Methods: This was a cross-sectional study carried out at the Douala General Hospital;the census of patients was carried out from 05 March to 10 May 2018. The data evaluated were knowledge and compliance with HDMs with an inference of their effect on blood pressure control. Results: We recruited 330 participants at mean age of 60 ± 11 years, 37.9% men;57.3% with blood pressure (BP) controlled. Out of 330 subjects, 308 (93.3%) who had been educated about dietary health measures for hypertension were assessed on knowledge, compliance and effect of these measures against 22 (6.7%) who had never heard about them. Around 85.7% of participants had good knowledge of HDMs and 78.9% had good compliance with them. There was no statistically significant influence of knowledge and compliance with HDMs on blood pressure control. Conclusion: The level of knowledge and adherence to HDMs of hypertensive patients at the Douala General Hospital was appreciable. It is however appropriate for physicians to intensify patient education on HDMs and BP control.